Thank you; the data from the city directory matches nicely with Census data. I have had no luck with the 1910 Census either.
As to Joan Benoit, from a thread I found on the Benoit forum, she would seem to be my fourth cousin. She seems to be a descendent of Arthur Benoit, son of Charles and Emélie Clément, whereas my great-great-great-grandfather was Arthur's brother Albert. I have no proof yet, but I strongly suspect that Henri, Eugène, and Oscar were all brothers, sons of Arthur Benoit and Parmélie Fréchette. There may have been another brother named Robert, who lived in Portland in 1920, and in Malden, Massachusetts, in 1930.